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Biomedical subjects

T K Truong

Publications and source records attributed to T K Truong.

At least 19 recordsLinked to original sources
PubMed2001

Down-regulation of promoter 1.3 activity of the human aromatase gene in breast tissue by zinc-finger protein, snail (SnaH).

Aromatase (estrogen synthetase) is expressed in breast cancer tissue, and in situ expression of the enzyme stimulates breast cancer growth. Promoter I.3 is one of the major promoters that control the expression of aromatase in breast cancer tissue. Using the yeast one-hybrid approach to screen a human breast tissue hybrid cDNA expression library, we found that the zinc-finger transcriptional factor Snail (SnaH) interacted with a regulatory region near promoter I.3 of the human aromatase gene. DNA mobility shift assays and mutation analyses using recombinant SnaH protein expressed in Escherichia coli have revealed that this protein interacts with a segment, 5'-CTGATGAAGT-3', which is between 66 and 76 bp upstream from the transcriptional start site of promoter I.3. Using mammalian cell transfection experiments, SnaH was found to act as a repressor of promoter I.3 activity. Site-directed mutagenesis experiments have revealed that the NH2-terminal SNAG domain is important for the repressor activity of SnaH. To demonstrate the inhibitory activity against aromatase expression, a stable SnaH-expressing MDA-MB-231 breast cancer cell line was generated, and the aromatase RNA messages in the SnaH-transfected cell line were found to be 30% of those in the vector-transfected cell line. Reverse transcription-PCR analysis on RNAs isolated from 12 cell lines has confirmed that SnaH is expressed at a higher level in normal breast epithelial cell and stromal fibroblast cell lines than in breast cancer cell lines. In addition, SnaH mRNA was detected in only 16 of 55 breast cancer specimens. On the other hand, aromatase mRNA was detected in 54 of the 55 specimens. Our results indicate that SnaH acts as a repressor that down-regulates the expression of aromatase in normal breast tissue by suppressing the function of promoter I.3. A reduction of the expression of SnaH in breast cancer tissue further suggests a cancer-protective role for this protein in normal breast tissue.

Amino Acid Sequence↗
PubMed2001

The application of the neural network on Morse code recognition for users with physical impairments.

Morse code is a simple, speedy and low cost means of communication composed of a series of dots, dashes and space intervals. Each tone element (either a dot, dash or space interval) is transmitted by sending a signal for a defined length of time. This poses a challenge as the automatic recognition of Morse code is dependent upon maintaining a stable typing rate. In this paper, a suitable adaptive automatic recognition method, combining the least-mean-square (LMS) algorithm with a neural network, was applied to this problem. The method presented in this paper is divided into five modules: space recognition, tone recognition, learning process, adaptive processing and character recognition. Statistical analyses demonstrated that the proposed method elicited a better recognition rate in comparison with other methods in the literature.

Algorithms↗
PubMed1985

VLSI architectures for computing multiplications and inverses in GF(2m).

Finite field arithmetic logic is central in the implementation of Reed-Solomon coders and in some cryptographic algorithms. There is a need for good multiplication and inversion algorithms that can be easily realized on VLSI chips. Massey and Omura recently developed a new multiplication algorithm for Galois fields based on a normal basis representation. In this paper, a pipeline structure is developed to realize the Massey-Omura multiplier in the finite field GF(2m). With the simple squaring property of the normal basis representation used together with this multiplier, a pipeline architecture is developed for computing inverse elements in GF(2m). The designs developed for the Massey-Omura multiplier and the computation of inverse elements are regular, simple, expandable, and therefore, naturally suitable for VLSI implementation.

Algorithms↗
PubMed1985

A VLSI design of a pipeline Reed-Solomon decoder.

A pipeline structure of a transform decoder similar to a systolic array is developed to decode Reed-Solomon (RS) codes. An important ingredient of this design is a modified Euclidean algorithm for computing the error-locator polynomial. The computation of inverse field elements is completely avoided in this modification of Euclid's algorithm. The new coder is regular and simple, and naturally suitable for VLSI implementation. An example illustrating both the pipeline and systolic array aspects of this decoder structure is given for a RS code.

Algorithms↗